It is known that the presence of infarcted regions of myocardium can result in fatal arrhythmias with little or no warning. This project seeks to correlate the 3-dimensional configuration of infarcts with onset of sudden arrhythmia. This will be done initially using high-resolution (0.2-0.3mm spatial resolution) isotropic 3D NMR imaging at high field of fixed human hearts. High field imaging will permit acquisition of images with adequate signal-to-noise ratio while maintaining very high spatial resolution. Initial experiments have demonstrated the ability to clearly visualize infarcted regions within (what had been) normal tissue of fixed hearts (formalin) using T1 weighted NMR imaging. This study may lead to high resolution ventricular function imaging of paced infarct animal models using imaging techniques developed under Core Project III (Imaging of Physiological Function).